Performance, power and 0-100 km/h
2026 BMW M3 Competition xDrive has the quicker recorded 0-100 km/h time at 3.4 seconds, compared with 4.4 seconds for 2026 Mercedes-Benz S-Class S 580 4MATIC. 2026 BMW M3 Competition xDrive has the higher listed output at 530 hp; 2026 Mercedes-Benz S-Class S 580 4MATIC is rated at 503 hp, a difference of 27 hp. The torque figures follow 2026 Mercedes-Benz S-Class S 580 4MATIC at 700 Nm and 2026 BMW M3 Competition xDrive at 650 Nm. These figures describe straight-line potential only; they do not establish braking performance, ride quality, steering response or durability under repeated hard use.
Range, battery, charging and efficiency
2026 Mercedes-Benz S-Class S 580 4MATIC has the lower recorded consumption at 9.0 L/100km; 2026 BMW M3 Competition xDrive is listed at 10.2 L/100km. Test cycle, temperature, wheel size and charging conditions can materially affect these results, so only figures measured on the same basis should be treated as directly comparable.
Dimensions, cargo space and towing
2026 Mercedes-Benz S-Class S 580 4MATIC provides the larger quoted cargo volume: 550 litres versus 480 litres, a difference of 70 litres. 2026 Mercedes-Benz S-Class S 580 4MATIC is 495 mm longer overall. Exterior size is not a benefit by itself: a longer body may create useful room, but cargo shape, rear-seat space and ease of parking still require a physical inspection.
Price and overall assessment
2026 BMW M3 Competition xDrive has the lower listed starting price at $80,900, compared with $128,400 for 2026 Mercedes-Benz S-Class S 580 4MATIC. 2026 BMW M3 Competition xDrive leads in more of the shared headline fields, but that is not a universal verdict: a buyer should weight price, performance, range and utility rather than simply count category wins. The assessment is based on the specifications shown here; it is not presented as a two-car road test.